Wearable Thermoelectric Materials and Devices for Self‐Powered Electronic Systems

Abstract

Because of their readiness and high power bandwidth, batteries are the preeminent source of power supply for portable electronics, but are subject to periodic recharging and replacement. Hence, a key challenge is to design suitable and sustainable power sources for portable electronic devices. Harvesting energy from the human body is suitable for providing consistent and uninterrupted energy for wearable electronic devices. The daily activities of a 68-kg adult can generate over 100 W of power, through breathing, heating, blood transport, and walking. [3] Thus, converting 1% of the power generated by the human body may be enough to support the work of most portable electronics. Various energy-harvesting technologies, such as, triboelectric nanogenerators (TENGs), [4][5][6] piezoelectric nanogenerators, [7] and thermoelectric generators (TEGs), [8] have been developed to convert human energy (from human motion and body heat) into electricity. In line with recent developments in wearable electronics and e-skins, the use of a self-powered direct-current (DC) electric power supplier is inevitable for activating human body-adjustable electronic systems. [9] Among the various energy-autonomous devices, [10] only TEGs can permanently produce DC electric power without complex power managing components, and they are maintenance free. Moreover, solar energy and vibration-based energy harvesters areThe emergence of artificial intelligence and the Internet of Things has led to a growing demand for wearable and maintenance-free power sources. The continual push toward lower operating voltages and power consumption in modern integrated circuits has made the development of devices powered by body heat finally feasible. In this context, thermoelectric (TE) materials have emerged as promising candidates for the effective conversion of body heat into electricity to power wearable devices without being limited by environmental conditions. Driven by rapid advances in processing technology and the performance of TE materials over the past two decades, wearable thermoelectric generators (WTEGs) have gradually become more flexible and stretchable so that they can be used on complex and dynamic surfaces. In this review, the functional materials, processing techniques, and strategies for the device design of different types of WTEGs are comprehensively covered. Wearable self-powered systems based on WTEGs are summarized, including multi-function TE modules, hybrid energy harvesting, and all-in-one energy devices. Challenges in organic TE materials, interfacial engineering, and assessments of device performance are discussed, and suggestions for future developments in the area are provided. This review will promote the rapid implementation of wearable TE materials and devices in self-powered electronic systems.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202102990.

All-polymer wearable thermoelectrochemical cells harvesting body heat

“…With the rapid development of next-generation wearable electronics, such as portable devices and soft electric devices, there is strong demand for lightweight, wearable, and environmentally friendly energy devices, such as piezoelectric nanogenerators, thermoelectric generators and thermoelectrochemical cells ( Dargusch et al., 2020 ; Shi et al., 2020 ; Khan et al., 2021 ; Jia et al., 2021 ; Tian et al., 2019 ; Zhang et al., 2021 ). Human body heat is an accessible, relatively consistent, and environmentally friendly power source with a temperature difference (ΔT) between human skin and ambient environment ( Oh et al., 2016 ; Zhong et al., 2014 ).…”

Recent Progress of Two-Dimensional Transition Metal Dichalcogenides for Thermoelectric Applications

“…With the increase in the demand for wearable and portable flexible devices, thin-film TE materials have received wide attention. Besides of high TE performance, there are many other criteria for flexible TE materials, like low cost, light weight, flexibility, stability, scalable, and easy preparation [132]. Inorganic materials have high TE performance, but they are inflexible [133,134].…”

Potential of Recycled Silicon and Silicon-Based Thermoelectrics for Power Generation

“…It is important to note that additional considerations should also be in place depending on the environment and situation that the thermoelectric module is utilized in. For commercial planes, there are multiple possible locations to install thermoelectric devices-the most common being the fuselage, where low-temperature thermoelectrics are utilized for powering WSNs [153,154]. Looking toward further usage of thermoelectrics in commercial aviation, models have been constructed around the installation of thermoelectric generators at the plane engine nozzles [109].…”